Download Activity 2.2.1: How Many Chambers Does It Have? Introduction

Activity 2.2.1: How Many Chambers Does It Have?
Introduction
The human heart is an amazing pump. Have you ever calculated how many times a
day your heart beats? Each beat is the pumping action of the heart as it moves
blood. On average, a person’s heart beats 100,000 times each day. That is over 35
million beats a year and over 2.5 billion beats during an average lifetime. The human
heart has to pump 5.6 liter (about six quarts) of blood every 20 seconds. In an
average lifetime the heart pumps over 55 million gallons of blood. That is a lot of
pumping!
The blood stream is the supply train for the body. Many of the resources necessary
for life are carried by the blood to all the cells in the body, including nutrients,
oxygen, and water. The body’s cells must carry out many metabolic reactions in
order to survive, grow, repair, or replicate. All of these processes require energy,
and oxygen is required for cells to obtain energy. Therefore, all cells need a constant
supply of oxygenated blood.
Recall the poster of the human body systems you and your classmates made earlier.
Think about how closely associated the cardiovascular and the respiratory systems
were. The blood cells in the cardiovascular system are oxygenated as they pass
through the lungs in the respiratory system.
The heart must move both oxygenated blood from the lungs to the body and unoxygenated blood from the body back to the lungs. The human heart has many
different components that work together to insure the proper movement of blood.
The structure of the four-chambered heart is designed so the oxygenated blood
does not mix with the un-oxygenated blood. The four-chambered design allows the
heart to act like two separate pumps keeping the oxygenated and un-oxygenated
blood from mixing. One pump moves blood from the heart to the lungs, and the
second pump moves blood from the heart to the body. The action of the two halves
or pumps of the heart must be carefully coordinated in order to keep the blood
circulating and going in the proper direction. To understand the design of the heart, it
is important to examine the structures of the heart and to study the direction of the
blood flow through the heart.
In this activity, you will make drawings of the structure of the heart and indicate the
direction of the blood flow through the heart. The diagrams you study and draw in
this activity will help you to identify the actual structures of the heart when you
dissect the four-chambered sheep’s heart in the next activity.
Equipment
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4 blank pieces of 8.5 x 11 inch paper
Colored pencils
An Illustrated Dissection Guide to the Mammalian Heart by David Hall or other
anatomy atlas of the heart.
PBS – Activity 2.2.1 How Many Chambers Does It Have - Page 1
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Computer with Internet access
Laboratory Journal
Procedure
At the completion of this activity, you should be able to:
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Identify the major structures in the human heart.
Identify the location of the major structures in the human heart.
Diagram the pathway the blood takes as it travels through the heart.
Describe the advantages the four-chambered structure of the heart provides for
blood flow and oxygen delivery.
1. Find diagrams of the human heart that show the ventral (front) and dorsal (back)
views of the organ and the direction of the flow of blood through it. Use the
Internet or other resources provided by your teacher. The websites listed below
may be useful resources for you.
o Yale University; Cardiothoracic Imaging: Gross Anatomy of the
Heart at: http://www.yale.edu/imaging/anatomy/ant_heart_2/
o Yale University, Cardiothoracic Imaging: Oblique View of the Heart
at: http://www.yale.edu/imaging/anatomy/oblique_heart/
2. Write the following titles on separate sheets of paper: Ventral View, Dorsal View,
Interior View, and Blood Flow. You will make four different drawings of the heart
as described below. The titles indicate the different views of the heart you will be
drawing.
3. Notice the column labeled Ventral View in the chart below. The items listed in this
column should be included and labeled on your drawing of the ventral view of the
heart.
4. Make your drawing of the ventral view of the heart using the diagrams you found
as resources.
5. Notice the column labeled Dorsal View in the chart below. The items listed in this
column should be included and labeled on your drawing of the dorsal view of the
heart.
6. Make your drawing of the dorsal view of the heart using the diagrams you found
as resources.
7. Notice the column labeled Interior View in the chart below. The items listed in this
column should be included and labeled on your drawing of the interior view of the
heart.
8. Make your drawing of the interior view of the heart using the diagrams you found
as resources.
9. Notice the column labeled Blood Flow in the chart below. The items listed in this
column should be included and labeled on your drawing of the blood flow through
the heart.
10. Make your drawing showing the direction the blood flows through the heart. Use
arrows to clearly show the blood flow pattern.
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11. Show your completed drawings to your teacher before proceeding to the next
step.
12. List in your Laboratory Journal all the structures you labeled on the four drawings
(use each term once). Construct your list so you will have room next to each term
to write a sentence or two.
13. Research, using the Internet or other given resources, the specific function of
each of the structures you listed. Next to the name of each structure, write one or
two sentences that describe the specific function of that structure.
Views of the Heart and Structures to Label for Each Drawing:
Ventral View
(Exterior)
Brachiocephalic
artery
Aorta
Brachiocephalic
artery
Blood Flow
Pattern
Pulmonary vein
(Right and left)
Aorta
Brachiocephalic
Artery
Superior vena cava
Left atrium
Right pulmonary
vein
Right atrium
Aorta
Left pulmonary vein
Inferior vena cava
Aortic semilunar
valve
Mitral (bicuspid)
valve
Aortic semilunar
valve
Pulmonary Artery
Right ventricle
Pulmonary vein
Left ventricle
Coronary artery
Coronary artery
Left atrium
Right ventricle
Left ventricle
Left ventricle
Mitral (bicuspid)
valve
Tricuspid valve
Inferior vena cava
Left atrium
Left ventricle
Inferior vena cava
Right ventricle
Pulmonary vein
Right ventricle
Pulmonary
semilunar valve
Right atrium
Pulmonary artery
Inferior vena cava
Right atrium
Myocardium
Superior vena cava
Tricuspid valve
Aorta
Superior vena cava
Dorsal View
(Exterior)
Interior View
Pulmonary
semilunar valve
PBS – Activity 2.2.1 How Many Chambers Does It Have - Page 3
Conclusion
1. In most of the body the arteries carry oxygenated blood and the veins carry unoxygenated blood. The exception to this pattern is the heart. Explain how and
why specific arteries and veins of the heart are different from the pattern seen in
the rest of the body.
2. Describe and explain the mechanisms in place to prevent the blood from flowing
in the wrong direction through the heart.
3. Propose suggestions of things that could affect specific heart structures that in
turn cause a malfunction in the flow of blood through the heart or the body?
4. Amphibians have a three-chambered heart; there is only one ventricle. Their
blood is pumped to their lungs from the ventricle, returned to the same ventricle
from the lungs, and then pumped to their body cells. Explain how and why the
four-chambered design of the mammalian heart is an improvement over the
three-chambered design.
PBS – Activity 2.2.1 How Many Chambers Does It Have - Page 4